#include "stdafx.h"
#include "xrtheora_stream.h"

#ifdef _EDITOR
//#	pragma comment(lib,	"x:\\oggB.lib")
//#	pragma comment(lib,	"x:\\theoraB.lib") 
#endif

CTheoraStream::CTheoraStream()                        
{
	// clear self
	source				= 0;
	fpms				= 0.f;
	d_frame				= -1;
	tm_total			= 0;
	key_rate			= 0;
	// start up Ogg stream synchronization layer
	ogg_sync_init		(&o_sync_state);
	// init supporting Theora structures needed in header parsing
	theora_comment_init	(&t_comment);
	theora_info_init	(&t_info);
	// clear struct
	Memory.mem_fill		(&o_stream_state,0,sizeof(o_stream_state));
	Memory.mem_fill		(&o_page,0,sizeof(o_page));
	Memory.mem_fill		(&t_state,0,sizeof(t_state));
	Memory.mem_fill		(&t_yuv_buffer,0,sizeof(t_yuv_buffer));
}

CTheoraStream::~CTheoraStream()
{
	ogg_sync_clear		(&o_sync_state);
	ogg_stream_clear	(&o_stream_state);
	theora_clear		(&t_state);
	theora_comment_clear(&t_comment);
	theora_info_clear	(&t_info);
	FS.r_close			(source);
}

void CTheoraStream::Reset()
{
	source->seek		(0);
	ogg_stream_reset	(&o_stream_state);
	ogg_sync_reset		(&o_sync_state);
	t_state.granulepos	= -1;
	d_frame				= -1;
}

int	CTheoraStream::ReadData()
{
	char *buffer		= ogg_sync_buffer(&o_sync_state,4096);
	long bytes			= 4096>(size_t)source->elapsed()?source->elapsed():4096;
	source->r			(buffer, bytes);	
	ogg_sync_wrote		(&o_sync_state,bytes);
	return bytes;
}

BOOL CTheoraStream::ParseHeaders		()
{
	ogg_packet			o_packet;
	int header_count	= 0;
	BOOL stateflag		= FALSE;

	// find Theora stream
	while(!stateflag){
		int ret			= ReadData(); 
		if (ret==0)		break;
		while(ogg_sync_pageout(&o_sync_state,&o_page)>0){
			ogg_stream_state test;

			// is this a mandated initial header? If not, stop parsing
			if(!ogg_page_bos(&o_page)){
				// don't leak the page; get it into the appropriate stream
				ogg_stream_pagein	(&o_stream_state,&o_page);
				stateflag			= 1;
				break;
			}

			ogg_stream_init		(&test,ogg_page_serialno(&o_page));
			ogg_stream_pagein	(&test,&o_page);
			ogg_stream_packetout(&test,&o_packet);

			// identify the codec: try theora 
			if(!header_count && theora_decode_header(&t_info,&t_comment,&o_packet)>=0){
				// it is theora 
				CopyMemory	(&o_stream_state,&test,sizeof(test));
				header_count	= 1;
			}else{
				// whatever it is, we don't care about it 
				ogg_stream_clear(&test);
			}
		}
		// fall through to non-bos page parsing 
	}

	// fail if theora stream not found in source
	if (0==header_count)		return FALSE;

	// we're expecting more header packets. 
	while((header_count && header_count<3)){
		int ret;

		// look for further theora headers 
		while(header_count && (header_count<3) && 0!=(ret=ogg_stream_packetout(&o_stream_state,&o_packet))){
			if(ret<0){
				fprintf(stderr,"Error parsing Theora stream headers; corrupt stream?\n");
				exit(1);
			}
			if(theora_decode_header(&t_info,&t_comment,&o_packet)){
				printf("Error parsing Theora stream headers; corrupt stream?\n");
				exit(1);
			}
			header_count++;
			if(header_count==3)break;
		}

		// The header pages/packets will arrive before anything else we
		// care about, or the stream is not obeying spec
		if(ogg_sync_pageout(&o_sync_state,&o_page)>0){
			ogg_stream_pagein	(&o_stream_state,&o_page);
		}else{
			int ret=ReadData(); // someone needs more data
			if(ret==0) FATAL	("End of file while searching for codec headers.");
		}
	}

	if (3!=header_count)	return FALSE;
	
	// init decode
	theora_decode_init		(&t_state,&t_info);
	// calculate frame per ms
	fpms					= ((float)t_info.fps_numerator/(float)t_info.fps_denominator)/1000.f;

	//. XXX hack (maybe slow)
	// calculate frame count & total length in ms & key rate
	ogg_int64_t	frame_count	= 0;
	ogg_int64_t p_key=0, c_key=0;
	while (TRUE){
		while(ogg_stream_packetout(&o_stream_state,&o_packet)>0){
			if ((0==key_rate)&&theora_packet_iskeyframe(&o_packet)){
				p_key		= c_key;
				c_key		= frame_count;
				key_rate	= (u32)(c_key-p_key);
			}
			frame_count++;
		}
		// check eof
		if (source->eof())	break;
		// no data yet for somebody.  Grab another page 
		if (0==ReadData())	break;
		while(ogg_sync_pageout(&o_sync_state,&o_page)>0)
			ogg_stream_pagein(&o_stream_state,&o_page);
	}
	tm_total				= iFloor(frame_count/fpms);

	// seek to 0
	Reset					();

	return TRUE;
}

BOOL CTheoraStream::Decode(u32 tm_play)
{
	VERIFY				(tm_play<tm_total);
	ogg_int64_t			t_frame;
	t_frame				= iFloor(tm_play*fpms);
	ogg_int64_t	k_frame	= t_frame-t_frame%key_rate;

	if (d_frame<t_frame){
		BOOL result		= FALSE;
		ogg_packet		o_packet;
		while (d_frame<t_frame){
			while(FALSE==result){
				// theora is one in, one out... 
				if(ogg_stream_packetout(&o_stream_state,&o_packet)>0 && !theora_packet_isheader(&o_packet)){
					d_frame++; 
					//. hack preroll
					if (d_frame<k_frame){		
//.						dbg_log				((stderr,"%04d: preroll\n",d_frame));
						VERIFY				((0!=d_frame%key_rate)||(0==d_frame%key_rate)&&theora_packet_iskeyframe(&o_packet));
						continue; 
					}
					BOOL is_key				= theora_packet_iskeyframe(&o_packet);
					VERIFY					( (d_frame!=k_frame) || ((d_frame==k_frame) && is_key) );
					// real decode
//.					dbg_log					((stderr,"%04d: decode\n",d_frame)); 
					int res					= theora_decode_packetin(&t_state,&o_packet);
					VERIFY					(res!=OC_BADPACKET);
//.					dbg_log					((stderr,"%04d: granule frame\n",theora_granule_frame(&t_state,t_state.granulepos)));
					if (d_frame>=t_frame)	result = TRUE;
				}else						break;
			}
			// check eof
			VERIFY(!(FALSE==result&&source->eof()));
			if(FALSE==result){
				// no data yet for somebody.  Grab another page 
				if (ReadData()){
					while(ogg_sync_pageout(&o_sync_state,&o_page)>0)
						ogg_stream_pagein	(&o_stream_state,&o_page);
				}
			}
		}
		// all right - get yuv buffer
		VERIFY								(TRUE==result);
		VERIFY								(d_frame==t_frame);
		theora_decode_YUVout				(&t_state,&t_yuv_buffer);
//.		dbg_log								((stderr,"%04d: yuv out\n",d_frame));
		return TRUE;
	}
	return FALSE;
}

BOOL CTheoraStream::Load(const char* fname)
{
	VERIFY				(0==source);
	// open source
#ifdef _EDITOR
	source				= FS.r_open(0,fname);
#else
	source				= FS.rs_open(0,fname);
#endif
	VERIFY				(source);

	// parse headers
	BOOL res			= ParseHeaders();
	// seek to start
	Reset				();
	return				res;
}

